It has become common to provide an article of luggage whose case or body is provided with wheels and which may have a handle which can extend from the luggage body and by which the article can be drawn along a surface.
Frequently the container portion of that article, i.e. the body, is composed of a low-wear fabric, for example, a nylon, or other soft material which can become damaged should the article encounter an obstruction in its path or impact against some other element. Most frequently that impact occurs toward the bottom and rear of the article and can cause damage to the latter. Of course the principles discussed herein are also applicable to rigid-case luggage since such articles also can be damaged by impact as the rolling article encounters an obstruction.
Problems with respect to manipulation of the article over an obstruction such as a step or a flight of stairs can be encountered when the surface along which the article is drawn is not a continuous ramp. Finally, especially with soft luggage, i.e. luggage in which the container is formed by a highly flexible material such as a fabric, problems are encountered with respect to the shape retention or structuring of the article.
All of these problems have generated a variety of efforts to solve them, although most of the conventional solutions have not been fully satisfactory.